You don't have to tell Madeline Kahn comedy is hard. Take the first episode of Cosby, in which her flighty character, Pauline, had to schlepp a hefty, slumbering Cos back and forth across the living room set. ''My muscles were a little strained,'' Kahn remembers. ''So [Cosby] gave me two massages. Oh, not personally. You mustn't suggest that.''
Cosby is wise to keep her happy. The 54-year-old Kahn, with her famously nasal voice and arched brows, provides a perfect counterpoint to Cosby's grumpathon. But she still seems surprised she's landed here. ''If left to my own devices, I would have found myself a tragedian,'' says the Boston-born actress whose early career included ultraserious Kurt Weill musicals. ''People assume I'm this farcical, broad person, which I'm not.''
For that, blame Mel Brooks. After a chance meeting at the Warner Bros. commissary, the director plopped the redhead into Young Frankenstein, High Anxiety, and perhaps most memorably, Blazing Saddles, where her Teutonic tramp Lili Von Shtupp belted out the notoriously naughty ''I'm Tired.'' (''I never tire of it,'' she says. ''I still sing it.'') Despite some discussions with Brooks, Kahn steered clear of his later work, apparently finding it as wince inducing as the rest of us. ''It's hard to continue to find life amusing,'' Kahn suggests diplomatically. ''Things happen that tend to dampen your outlook.''
The actress has had her own career disappointmentsat least on TV (Oh Madeline, New York News). Then Cosby came calling. Attracted by the message of races mingling comfortably, Kahn snapped up the role. Her only complaint? The breakneck pace, which means she can't dig out all her character's nuances. ''What I see in the work that's interesting are the uncomfortable elements,'' she says. Take Pauline. A zany, carefree neighbor? Not to Kahn: ''I feel her background was troubled...I see her as a kind of isolated person in our urban culture.'' Comedy can be hard.